I need help with this word problem

Question

A nurse mixes 70cc of a 50%saline solution with a 10% saline solution to produce a 26%

 saline solution. How much of the 10% solution should he use?

Answer 1

.5(70)+ .1x = .26(70+x)

.16x =.24(70)= 16.8

x=16.8/.16= 105 cc

3/2= x/70

x= 105 cc of 10%